elementUI Dialog 固定高度

<el-dialog
  title="提示"
  :visible.sync="dialogVisible"
  width="30%"
  :before-close="handleClose">
  <div class="el-dialog-div">这是一段信息</div>
  <span slot="footer" class="dialog-footer">
    <el-button @click="dialogVisible = false">取 消</el-button>
    <el-button type="primary" @click="dialogVisible = false">确 定</el-button>
  </span>
</el-dialog>

.el-dialog-div {
  height: 70vh;
  overflow: auto;
}